✔ 最佳答案
Refer to the figure below.
Draw OP as shown which is the perpendicular bisector of LM.
Join OM. OM = 2 as OM is a radius of the circle.
In ΔHOP:
sin(30°) = OP/OH
OP = OH sin(30°)
OP = (1 + 2) × (1/20
OP = 3/2
In ΔOPM:
PM² + OP² = OM² (Pythagorean theorem)
PM² + (3/2)² = 2²
PM² = 7/4
PM = (1/2)√7
x = 2 PM
x = 2 * (1/2)√7
x = √7
x ≈ 2.646